JP5217894B2 - Sheet folding apparatus and image forming system - Google Patents

Description

  The present invention relates to a sheet folding apparatus that performs various types of folding on a sheet, an image forming apparatus that forms a read image on a sheet, and an image forming system including the sheet folding apparatus.

  In the sheet folding apparatus disclosed in Patent Document 1, the length of the sheet in the sheet conveyance direction is approximately 1 from one end and the other end in the sheet conveyance direction at the first folding unit having two folding nips formed by a plurality of folding rollers. The sheet is folded at a second folding portion having one folding nip formed by two folding rollers, and folding the sheet so that the one end and the other end are located on the same side with the position at a distance of / 4. Folding in the same direction as the folding is performed with the center position in the conveying direction as the folding position (quadrant folding).

  Further, a guide member is provided for guiding the sheet folded by the first folding portion to the folding nip of the second folding portion. The guide member is provided so as to be displaceable between a guide position for guiding the sheet to the folding nip and a retracted position retracted from the guide position, and the guide member is retracted when performing the final folding of the quadrant folding. The position is displaced from the guide position to the guide position.

JP 2001-88227 A

  However, in Patent Document 1, the folding roller of the second folding section is driven at the same linear speed (linear speed that prioritizes productivity) as the folding roller of the first folding section, so that the guide member for the conveyed sheet It is difficult to make the displacement timing appropriate.

  In other words, if the timing of displacing the guide member relative to the conveyed sheet is too early, the guide member will move the sheet before sufficient deflection is formed on the sheet. There is a problem that cannot be done. On the other hand, if the timing for displacing the guide member is too late, since the one folded end enters the other leading end side with respect to the folding position and enters the folding nip of the second folding portion, an accurate folding is performed. There is a problem that cannot be done.

  Therefore, the present invention provides a sheet folding apparatus capable of appropriately adjusting the timing of displacement of the guide member with respect to the conveyed sheet without significantly reducing productivity when the sheet is folded in quadruple on the sheet, and the sheet folding apparatus and image An object of the present invention is to obtain an image forming system including a forming apparatus.

In order to solve the above-described problem, the invention described in claim 1 includes a first folding unit that has a plurality of folding rollers that form two folding nips and folds the conveyed sheet, and one folding nip. And a guide member that guides the sheet to the folding nip of the second fold portion, and a guide member that folds the sheet folded by the first fold portion. The member can be displaced between a guide region for guiding the sheet and a retracted position retracted from the guide region, and the folding roller of the first folding unit and the folding roller of the second folding unit can be driven at different linear speeds. In the first folding portion, folding is performed such that the one end and the other end are positioned on the same side with a position at a distance of approximately 1/4 of the length in the sheet conveying direction from one end and the other end in the sheet conveying direction. And in the second fold When folding in the same direction as the folding with the center position in the sheet transport direction as the folding position, the linear velocity of the folding roller of the second folding section is set to the first speed after the driving of the folding roller of the second folding section is stopped. A sheet folding device that guides a sheet by displacing a guide member from a retracted position to a guide area after being slower than a linear speed of a folding roller of one folding part ,
A first folding motor that drives the folding rollers of the first folding section and the second folding section; and a second folding motor that drives the folding rollers of the second folding section, and the second folding section according to the selected folding mode. The driving source of the folding roller can be switched between the first folding motor and the second folding motor .

According to a second aspect of the present invention, in the first aspect of the present invention, the folding roller of the second folding portion is connected to the first folding motor via the first clutch and via the second clutch. The second folding motor is connected to the second folding motor, and the drive source of the second folding roller can be switched between the first folding motor and the second folding motor by turning on and off the first clutch and the second clutch. .

According to a third aspect of the present invention, in the first or second aspect of the present invention, a sheet detecting means is provided between the final folding nip of the first folding portion and the folding nip of the second folding portion in the sheet conveyance path. When the sheet detecting means detects the sheet, drive control of the folding roller of the second folding unit is started .

According to a fourth aspect of the present invention, in the invention according to the third aspect , the sheet detecting means is configured to convey the minimum sheet size in the conveyance direction along the sheet conveyance path from the folding nip of the second folding portion. It is characterized in that it is provided at a position of a distance of 1/4 .

The invention described in claim 5 is the invention described in claim 3 or 4 , further comprising a regulating member that determines a folding position in the second folding section, and regulates the leading edge of the sheet folded in the first folding section. The guide member is displaced from the retracted position to the guide region after the sheet is abutted against the member and fed by a predetermined amount or bent .

The invention described in claim 6 is characterized in that, in the invention described in claim 5 , the sheet feed amount after abutting against the regulating member is set to 5 mm to 20 mm .

The invention described in claim 7 is characterized in that, in the invention described in claim 5 or 6 , the sheet feed amount after abutting against the regulating member is increased as the thickness of the sheet is increased .

The invention described in claim 8 is the invention described in any one of claims 3 to 7 , wherein the linear velocity of the folding roller of the second folding portion is slower than the linear velocity of the folding roller of the first folding portion. In this case, the linear speed of the folding roller of the second folding unit is reduced only while the sheet detecting unit detects the sheet .

The invention described in claim 9 is the invention described in any one of claims 3 to 8 , wherein the linear velocity of the folding roller of the second folding portion is slower than the linear velocity of the folding roller of the first folding portion. In this case, the displacement of the guide member from the retracted position to the guide area is completed while the linear speed of the folding roller of the second folding section is completed while the linear speed of the folding roller of the second folding section is reduced to the first folding speed. The guide member is displaced from the guide region to the retracted position after the same linear velocity of the roller .

A tenth aspect of the invention includes an image forming apparatus that forms a read image on a sheet, and the sheet folding apparatus according to any one of the first to ninth aspects. An image forming system in which a formed sheet is folded by the sheet folding apparatus .

  According to the present invention, when the final folding of the Kannon quadruple is performed, after the driving of the folding roller of the second folding unit is stopped, or the linear velocity of the folding roller of the second folding unit is set to the folding roller of the first folding unit. Since the sheet is guided to the folding nip of the second folding part by moving the guide member from the retracted position to the guiding position after being made slower than the linear speed, the sheet can be conveyed without significantly detracting from the productivity of the quadruple fold. The timing of displacement of the guide member with respect to the coming sheet can be made appropriate.

  Hereinafter, a first embodiment of the present invention will be described in detail with reference to the accompanying drawings. FIG. 1A is a longitudinal sectional view around the second folding portion of the sheet folding apparatus according to the first embodiment, and shows a state in which the sheet leading edge is detected by the sheet sensor. FIG. 1B is a longitudinal sectional view around the second folding portion of the sheet folding apparatus according to the first embodiment, and shows a state in which the leading end of the sheet is in contact with the regulating member. FIG. 2A is a longitudinal sectional view around the second folding portion of the sheet folding apparatus according to the first embodiment, and shows a state in which the sheet is guided to the third folding nip. FIG. 2B is a longitudinal sectional view of the vicinity of the second folding portion of the sheet folding apparatus according to the first embodiment, and shows a state where the sheet is conveyed while being sandwiched by the third folding nip. FIG. 3 is a longitudinal sectional view around the first fold and the second fold according to the first embodiment, and shows the drive configuration of the first fold drive roller and the second fold drive roller. FIG. 4 is a plan view of the periphery of the first and second folding portions according to the first embodiment, and is a diagram showing the drive configuration of the first and second folding driving rollers. FIG. 5 is a longitudinal sectional view showing a schematic configuration of the sheet folding apparatus according to the first embodiment. FIG. 6 is a block diagram illustrating a control configuration of the sheet folding apparatus according to the first embodiment, and FIG. 7 is a flowchart illustrating control of the sheet folding apparatus according to the first embodiment.

  As shown in FIG. 5, the image forming system 1 according to the first embodiment includes an image forming apparatus 3, a sheet folding apparatus 5 that performs various folds on a sheet image-formed by the image forming apparatus 3, and an image forming apparatus. 3 and a sheet binding device 7 that binds a sheet on which an image is formed or a sheet that has been subjected to various folds by the sheet folding device 5.

  The image forming apparatus 3 is a copying machine, and supplies an image reading unit that reads an image of an original, an image forming unit that forms an image of the original read by the image reading unit on a sheet (paper), and an image forming unit. And a sheet storage portion for storing the sheet. The image forming apparatus 3 is provided with an operation panel 4 and a main body control unit 6 (see FIG. 6), and an operation signal from the operation panel 4 is transmitted to the main body control unit 6. . A contact glass on which a document is set is provided above the image reading unit.

The sheet folding device 5 is provided with a sheet receiving port 9 for receiving a sheet after image formation from the image forming device 3, and a downstream side of the sheet receiving port 9 is a transport destination of the sheet carried from the sheet receiving port 9. A first switching claw 11 that switches to the transport path 13 or the second transport path 15 is provided.
A third conveyance path 17 is continuous with the downstream end of the first conveyance path 13, and the first conveyance path 13 or the third conveyance is located near the continuous portion between the first conveyance path 13 and the third conveyance path 17. A first folding unit 19 that folds the sheet conveyed from the path 17 is provided. A first stopper 57 is provided in the third conveyance path 17 so as to regulate the leading edge of the sheet conveyed to the third conveyance path 17. The first stopper 57 is configured to move in the sheet conveying direction according to the folding mode and the sheet size. A fourth conveyance path 21 and a fifth conveyance path 23 are continuous with the first folding portion 19, and a sixth conveyance path 25 and a seventh conveyance path 27 are continuous with the downstream end of the fifth conveyance path 23. ing. The fourth transport path 21 is provided with a second stopper 59 to regulate the leading edge of the sheet transported to the fourth transport path 21. The second stopper 59 moves in the sheet conveying direction according to the folding mode and the sheet size. A second switching claw 29 is provided on the downstream side of the fifth conveyance path 23 to switch the sheet conveyance destination to the sixth conveyance path 25 and the seventh conveyance path 27. A second folding unit 31 that folds the sheet is provided on the downstream side of the sixth conveyance path 25. An eighth conveyance path 33 and a ninth conveyance path 35 are continuous with the second folding unit 31, and the ninth conveyance path 35 joins the seventh conveyance path 27 and continues to the tenth conveyance path 37. Yes. A third stopper 61 is provided in the eighth conveyance path 33 so as to regulate the leading edge of the sheet conveyed to the eighth conveyance path 33. The third stopper 61 moves in the sheet conveying direction according to the folding mode and the sheet size. The downstream end of the tenth transport path 37 is continuous with the eleventh transport path 39 and the twelfth transport path 41. A third switching claw 43 that switches the sheet conveyance destination to the eleventh conveyance path 39 or the twelfth conveyance path 41 is provided on the downstream side of the tenth conveyance path 37. The eleventh conveyance path 39 joins the second conveyance path 15 and continues to the thirteenth conveyance path 45, and the thirteenth conveyance path 45 continues to the sheet discharge unit 47. A fourth switching claw 44 is provided on the downstream side of the eleventh conveyance path 39 so that the sheet is guided to the thirteenth conveyance path 45. The twelfth conveyance path 41 is continuous with the sheet carry-in port 49 of the sheet binding device 7. The first transport path 13, the second transport path 15, the fifth transport path 23, the seventh transport path 27, the ninth transport path 35, the tenth transport path 37, the eleventh transport path 39, and the thirteenth transport path 45. Is provided with a transport roller.

  The sheet binding device 7 is provided with a staple tray that temporarily discharges sheets, a stapler that binds the end of the sheet bundle stacked on the staple tray, and a paper discharge tray that discharges sheets. The sheet is discharged after the end of the sheet bundle is bound.

  As shown in FIG. 3, the first folding section 19 is provided with a first folding driving roller 51a and first folding driven rollers 51b and 51c driven by the first folding driving roller 51а. The first folding driven rollers 51b and 51c are in pressure contact with the first folding driving roller 51a.

  In addition, a guide for guiding the leading edge of the sheet to the first fold nip 52 is provided in the conveyance path so as to be able to appear in the conveyance path, in the immediate vicinity of the first fold nip 52 between the first fold driving roller 51a and the first fold driven roller 51b. A guide for guiding the leading edge of the sheet to the second folding nip 54 is provided in the conveyance path so as to be able to appear and retract in the conveyance path in the immediate vicinity of the second folding nip 54 between the first folding driving roller 51a and the first folding driven roller 51c. It has been.

  The second folding unit 31 is provided with a second folding driving roller 53a, a second folding driven roller 53b driven by the second folding driving roller 53a, and a second driven roller 55 driven by the second folding driven roller 53b. ing. The second folding driven roller 53b is in pressure contact with the second folding driving roller 53a, and the second driven roller 55 is in pressure contact with the second folding driven roller 53b.

  As shown in FIG. 4, the shaft of the first folding drive roller 51 a is fixed to the first pulley 56, and the shaft of the second folding drive roller 53 a is connected to the second pulley 58 via the first electromagnetic clutch 67. ing. A first timing belt 63 is wound around the first pulley 56 and the second pulley 58, and the first timing belt 63 is driven by a first folding motor (DC motor) 65.

  By turning on / off the first electromagnetic clutch 67, drive transmission from the first folding motor 65 to the second folding drive roller 53a can be turned on / off. The first folding motor 65 and the first electromagnetic clutch 67 are controlled by the control unit 75.

  The second folding driving roller 53a is connected to the third pulley 60 via a second electromagnetic clutch 73, and the third pulley 60 is connected to a second folding motor (stepping motor) via a second timing belt 69. 71 is driven.

  By turning on / off the second electromagnetic clutch 73, drive transmission from the second folding motor 71 to the second folding drive roller 53a can be turned on / off. The second folding motor 71 and the second electromagnetic clutch 73 are controlled by the control unit 75.

  When the first electromagnetic clutch 67 is turned on and the second electromagnetic clutch 73 is turned off, the drive of the first folding motor 65 is transmitted to the second folding drive roller 53a, and the first electromagnetic clutch 67 is turned off and When the second electromagnetic clutch 73 is turned on, the drive of the second folding motor 71 is transmitted to the second folding driving roller 53a.

  Thereby, the drive source of the second folding drive roller 53a can be switched between the first folding motor 65 and the second folding motor 71.

  As shown in FIG. 1, the second folding drive roller 53a and the second folding driven roller 53b are provided in the vicinity of the second driven roller 55 of the second folding unit 31 when the sheet is folded in the last four times. A guide member 77 for guiding the sheet is provided in the nip (third folding nip) 78.

  The guide member 77 is pivotally supported at one end thereof, and is driven by a guide member drive motor (stepping motor) 79 to contact the center of the sheet and guide the sheet to the third folding nip. It rotates (displaces) between the guide area and the retracted position retracted from the guide area. The guide member drive motor 79 is driven by the control unit 75.

  The longitudinal section of the portion of the guide member 77 that contacts the central portion of the sheet has a substantially triangular shape. As the guide member 77 rotates from the retracted position to the guide region, the top 80 on the third folding nip 78 side is It approaches the third folding nip 78.

  In the eighth conveyance path 33, a sheet sensor (optical sensor) 81 is provided from the third folding nip 78 at a position that is a distance of ¼ of the conveyance direction length P of the minimum acceptable sheet (for example, B5 size). Is provided. The sheet sensor 81 is connected to the control unit 75 and transmits a sheet detection signal.

  The configuration of the control unit 75 will be described with reference to FIG. The receiving unit 83 receives signals from the main body control unit 6 and the sheet sensor 81. The determination unit 85 determines a situation based on information from the reception unit 83, a drive pulse number counting unit 87 described later, and a timer 90. The drive pulse number counting unit 87 counts the number of drive pulses of the second folding motor 71 after the sheet sensor 81 detects the leading edge of the sheet. The timer 90 starts measuring time when the sheet sensor 81 detects the leading edge of the sheet. The processing unit 89 executes processing according to the determination of the determination unit 85. The transmission unit 91 transmits the processing content of the processing unit 89 to the first folding motor 65, the second folding motor 71, the first electromagnetic clutch 67, the second electromagnetic clutch 73, and the guide member drive motor 79. The determination unit 85 determines that a jam has occurred when the sheet sensor 81 remains in a detection state for a predetermined time (for example, 5 seconds).

  On the operation panel 4 of the image forming apparatus 3, a folding mode, a binding mode, and a straight discharge mode can be selected. Further, in the folding mode, two-fold, Z-fold, outer three-fold, inner three-fold, simple Each folding mode can be selected from the four-fold and the Kannon quad-fold.

  The operation of the sheet folding apparatus 5 according to the present embodiment will be described with reference to FIGS. First, a case where the sheet is folded in quadrilateral will be described. When the user selects the folding mode on the operation panel 4 of the image forming apparatus 3, the determination unit 85 determines that the folding mode is set (S 1), and the processing unit 89 causes the first folding motor 65 and the second folding motor 71. Is started (S2). The first folding motor 65 and the second folding motor 71 are driven at the same linear speed (linear speed giving priority to productivity). In the initial state, the first electromagnetic clutch 67 and the second electromagnetic clutch 73 are off. Subsequently, the Kannon quad folding mode is selected from the folding modes. At this time, the determination unit 85 determines that the four-fold folding mode is selected (S3), and the processing unit 89 turns on the second electromagnetic clutch 73 (S4). Thus, the first folding drive roller 51a is driven by the first folding motor 65, and the second folding driving roller 53a is driven by the second folding motor 71.

  Then, when the user sets an original on the contact glass on the upper side of the image reading unit and presses the paper feed button on the operation panel 4, for example, an A4 size sheet is sent out from the sheet storage unit toward the image forming unit, The image forming unit forms an image of the document read by the image reading unit on a sheet.

  Thus, the sheet on which the image is formed by the image forming apparatus 3 is carried into the sheet folding apparatus 5 from the sheet receiving port 9. The carried-in sheet is guided to the first conveyance path 13 by the first switching claw 11 and is conveyed through the third conveyance path 17 as it is. The leading edge of the sheet comes into contact with the first stopper 57 standing by at a distance of about 3/4 of the length in the sheet conveyance direction from the first folding nip 52, and the bent portion of the sheet enters the first folding nip 52. To do. As a result, the first folding is performed with the position at a distance of approximately 1/4 of the length in the sheet conveying direction from one end in the sheet conveying direction as the folding position. The sheet that has been folded for the first time is conveyed through the fourth conveying path 21, and the front end of the sheet is waiting at a position that is approximately a half of the length in the sheet conveying direction from the second folding nip 54. The sheet abuts against the second stopper 59 and the bent portion of the sheet enters the second folding nip 54. As a result, the second folding is performed with the position at a distance of approximately 1/4 of the length in the sheet conveying direction from the other end in the sheet conveying direction as the folding position. The second folded sheet passes through the fifth conveyance path 23, is guided by the second switching claw 29, and is conveyed to the eighth conveyance path 33 through the sixth conveyance path 25. When the leading edge of the sheet that has entered the eighth conveyance path 33 reaches a position facing the sheet sensor 81 (see FIG. 1A), the determination unit 85 determines that the leading edge of the sheet has been detected (S5). The unit 85 determines whether or not the sheet has been conveyed a predetermined distance (L + α (5 mm to 20 mm)) after the leading edge of the sheet is detected (S6). The third stopper 61 stands by at a position at a distance L from the sheet sensor 81 and at a position at a distance of about ¼ of the length in the sheet conveyance direction from the third folding nip 78. The determination unit 85 makes this determination based on whether or not the drive pulse number counting unit 87 has counted the number of drive pulses corresponding to the predetermined distance (L + α). If it is determined that the sheet has been conveyed a predetermined distance (L + α) after detecting the leading edge of the sheet (see FIG. 1B), the processing unit 89 stops driving the second folding motor 71 (S7), and then the guide member 77. Is rotated from the retracted position to the guide area (S8).

  The sheet conveyed by the predetermined distance (L + α) from the sheet sensor 81 is formed with an appropriate bend, and the guide member 77 abuts against the bend while rotating in the direction of arrow J in FIG. The center of the sheet is pushed toward the third folding nip 78. The rotation of the guide member 77 is stopped at the maximum rotation position in the guide area.

  At this time, the conveyance of the sheet is stopped, and the guide member 77 starts abutting in a state in which the sheet is appropriately bent. Therefore, the leading end of the sheet folded inward by the first and second folds. And the guide member 77 can be optimized in positional relationship. That is, it is possible to prevent the first and second folding positions from being shifted and the U-shaped folding from occurring, and the leading end portion of the sheet folded inside by the first and second folding is the top portion 80 of the guide member 77. It is possible to prevent the breakage of the tip due to straddling.

  The center portion of the sheet is guided by the guide member 77 and enters the third folding nip 78, and the third folding (the last of the four-fold folding) is performed.

  When the rear end of the sheet reaches the position facing the sheet sensor 81 and the determination unit 85 determines that the rear end of the sheet has been detected (S9), the processing unit 89 starts driving the second folding motor 71 (S10). Then, the guide member 77 is rotated from the guide area toward the retracted position (S11).

  The third folded sheet is conveyed through the ninth conveyance path 35 and the tenth conveyance path 37 and guided to the eleventh conveyance path 39 or the twelfth conveyance path 41 by the third switching claw 43. The sheet guided to the eleventh transport path 39 is further guided to the thirteenth transport path 45 by the fourth switching claw 40 and discharged to the sheet discharge section 47. On the other hand, the sheet guided to the twelfth conveyance path 41 is conveyed from the sheet carry-in port 49 into the sheet binding device 7, stacked on a staple tray as necessary, and subjected to binding processing at the end of the sheet bundle by the stapler. The paper is discharged to the paper discharge tray.

  Next, a case where the sheet is subjected to folding other than quadruple folding will be described. When the user selects the folding mode on the operation panel 4, the determination unit 85 determines that the folding mode is selected (S1), and the processing unit 89 drives the first folding motor 65 and the second folding motor 71 (S2). ). Subsequently, when a folding mode other than the quadrifold folding is selected on the operation panel 4, the determination unit 85 determines that the quadruple folding mode is not set (S3), and the processing unit 89 turns on the first electromagnetic clutch 67 (S12). ). Thus, the first folding drive roller 51a and the second folding drive roller 51b are driven by the first folding motor 65 at a linear speed that gives priority to productivity.

  When the Z-folding mode is selected on the operation panel 4, the sheet on which the image is formed by the image forming apparatus 3 enters the sheet folding apparatus 5 from the sheet receiving port 9, and enters the first conveyance path 13 by the first switching claw 11. Guided. The sheet conveyed through the first conveyance path 13 is guided by a guide (not shown), enters the first folding nip 52, and is conveyed toward the fourth conveyance path 21. The sheet hits the second stopper 59 that is waiting at a position that is approximately ¼ of the length in the sheet conveyance direction from the second folding nip 54, and the bent portion enters the second folding nip 54. In this way, the first folding is performed with the position at a distance of approximately 1/4 from one end in the sheet conveying direction as the folding position. The first folded sheet is conveyed to the eighth conveyance path 33 through the fifth conveyance path 23 and the sixth conveyance path 25. The sheet hits the third stopper 61 that is waiting at a position that is approximately a half of the length in the sheet conveyance direction from the third folding nip 78, and the bent portion enters the third folding nip 78. In this way, the second folding in the direction opposite to the first folding is performed with the position at a distance of approximately 1/4 of the length in the sheet conveying direction from the other end of the sheet conveying direction as the folding position. Folding is complete. The second folded sheet is guided to the eleventh conveyance path 39 or the twelfth conveyance path 41 by the third switching claw 43 through the ninth conveyance path 35 and the tenth conveyance path 37. The sheet guided to the eleventh conveyance path 39 is guided to the sheet discharge section 47 by the fourth switching claw 44. The sheet guided to the twelfth conveyance path 41 is conveyed to the sheet binding device 7, and is bound as necessary, and then discharged to the paper discharge tray.

  When the two-fold mode is selected on the operation panel 4, a sheet on which an image is formed by the image forming apparatus 3 enters the sheet folding apparatus 5 from the sheet receiving port 9, and the first conveyance path 13 is moved by the first switching claw 11. Be guided to. The sheet conveyed through the first conveyance path 13 is conveyed toward the third conveyance path 17 as it is. The sheet hits the first stopper 57 standing by at a distance of half the length in the sheet conveyance direction from the first folding nip 52, and the bent portion enters the second folding nip 54. In this way, the first folding is performed with the position at a distance approximately half the length in the sheet conveying direction from one end in the sheet conveying direction being performed, and the two-folding is completed. The first folded sheet is guided by a guide (not shown), the leading end thereof enters the second folding nip 54, passes through the fifth conveyance path 23, and is changed by the second switching claw 29. 7 is guided to the transport path 27. The sheet conveyed through the seventh conveyance path 27 is guided to the eleventh conveyance path 39 or the twelfth conveyance path 41 by the third switching claw 43 through the tenth conveyance path 37. The sheet guided to the eleventh conveyance path 39 is guided to the sheet discharge section 47 by the fourth switching claw 44. The sheet guided to the twelfth conveyance path 41 is conveyed to the sheet binding device 7, and is bound as necessary, and then discharged to the paper discharge tray.

  When the outer three-fold mode is selected on the operation panel 4, the sheet on which the image is formed by the image forming apparatus 3 enters the sheet folding apparatus 5 from the sheet receiving port 9, and the first transfer path 11 13 will guide you. The sheet conveyed through the first conveyance path 13 is conveyed toward the third conveyance path 17 as it is. The sheet hits the first stopper 57 standing by at a distance of 1/3 of the length in the sheet conveyance direction from the first folding nip 52, and the bent portion enters the first folding nip 52. In this way, the first folding is performed with the position at a distance of approximately one third of the length in the sheet conveying direction from one end in the sheet conveying direction as the folding position. The second folded sheet is conveyed to the fourth conveyance path 21 and waits at a distance of about 1/3 of the sheet conveyance direction length from the third folding nip 78. 59, the bent portion enters the third folding nip 78. In this way, the second folding in the opposite direction to the first folding is performed with the position at a distance of about 1/3 of the length in the sheet conveying direction from the other end in the sheet conveying direction as the folding position. Tri-folding is complete. The second folded sheet is guided to the seventh conveyance path 27 by the second switching claw 29 through the fifth conveyance path 23. The sheet conveyed through the seventh conveyance path 27 is guided to the eleventh conveyance path 39 or the twelfth conveyance path 41 by the third switching claw 43 through the tenth conveyance path 37. The sheet guided to the eleventh conveyance path 39 is guided to the sheet discharge section 47 by the fourth switching claw 44. The sheet guided to the twelfth conveyance path 41 is conveyed to the sheet binding device 7, and is bound as necessary, and then discharged to the paper discharge tray.

  When the inner three-fold mode is selected on the operation panel 4, the sheet on which the image is formed by the image forming apparatus 3 enters the sheet folding apparatus 5 from the sheet receiving port 9, and the first transfer path 11 13 will guide you. The sheet conveyed through the first conveyance path 13 is conveyed toward the third conveyance path 17 as it is. The sheet hits the first stopper 57 standing by at a position that is 2/3 of the length in the sheet conveyance direction from the first folding nip 52, and the bent portion enters the first folding nip 52. In this way, the first folding is performed with the position at a distance of about 2/3 of the length in the sheet conveyance direction from one end in the sheet conveyance direction. The first folded sheet is conveyed to the fourth conveying path 21 and waits at a distance of about 1/3 of the length in the sheet conveying direction from the third folding nip 78. The bent portion enters the third folding nip 78. In this way, the second folding in the same direction as the first folding is performed with the position at a distance of about 1/3 of the length in the sheet conveying direction from one end of the sheet conveying direction as the first folding. Folding is complete. The second folded sheet is guided to the seventh conveyance path 27 by the second switching claw 29 through the fifth conveyance path 23. The sheet conveyed through the seventh conveyance path 27 is guided to the eleventh conveyance path 39 or the twelfth conveyance path 41 by the third switching claw 43 through the tenth conveyance path 37. The sheet guided to the eleventh conveyance path 39 is guided to the sheet discharge section 47 by the fourth switching claw 44. The sheet guided to the twelfth conveyance path 41 is conveyed to the sheet binding device 7, and is bound as necessary, and then discharged to the paper discharge tray.

  When the simple four-fold mode is selected on the operation panel 4, the sheet on which the image is formed by the image forming apparatus 3 enters the sheet folding apparatus 5 from the sheet receiving port 9, and the first transfer path 11 13 will guide you. The sheet conveyed through the first conveyance path 13 is conveyed toward the third conveyance path 17 as it is. The sheet hits the first stopper 57 that is waiting at a position that is half the length of the sheet in the conveyance direction from the first folding nip 52, and the bent portion enters the first folding nip 52. In this way, the first folding operation is performed with the position at a distance approximately half the length in the sheet conveying direction from one end of the sheet conveying direction as the folding position. The first folded sheet is conveyed to the fourth conveying path 21 and waits at a distance of about 1/4 of the length in the sheet conveying direction from the third folding nip 78. The bent portion enters the third folding nip 78. In this manner, the second folding is performed with the position at a distance of approximately 1/4 of the length in the sheet conveyance direction from one end in the sheet conveyance direction, and the simple four-fold is completed. The second folded sheet is guided to the seventh conveyance path 27 by the second switching claw 29 through the fifth conveyance path 23. The sheet conveyed through the seventh conveyance path 27 is guided to the eleventh conveyance path 39 or the twelfth conveyance path 41 by the third switching claw 43 through the tenth conveyance path 37. The sheet guided to the eleventh conveyance path 39 is guided to the sheet discharge section 47 by the fourth switching claw 44. The sheet guided to the twelfth conveyance path 41 is conveyed to the sheet binding device 7, and is bound as necessary, and then discharged to the paper discharge tray.

  When the straight discharge mode is selected on the operation panel 4, a sheet on which an image is formed by the image forming apparatus 3 enters the sheet folding apparatus 5 from the sheet receiving port 9, and the second conveyance path 15 is moved by the first switching claw 11. Be guided to. The sheet conveyed through the second conveyance path 15 is guided to the eleventh conveyance path 39 by the fourth switching claw 44, conveyed through the eleventh conveyance path 39 toward the sheet binding device 7, and bound as necessary. After being applied, the paper is discharged to a paper discharge tray.

  The operational effects of the first embodiment will be described. According to the first embodiment, when the final folding of the quadrant folding is performed, the driving of the second folding drive roller 53a is stopped, and then the guide member 77 is displaced from the retracted position to the guide region to change the sheet to the first position. Guide to the two-fold nip 54. Therefore, the rotation timing of the guide member 77 with respect to the conveyed sheet can be made appropriate without significantly impairing the productivity of the guanyin fold. Accordingly, the first and second folding positions can be prevented from shifting and the U-shaped folding can be prevented, and the leading end portion of the sheet that is folded inward by the first and second folding is the top portion 80 of the guide member 77. It is possible to prevent the breakage of the tip due to straddling.

  Since the drive source of the second folding drive roller 53a can be switched between the first folding motor 65 and the second folding motor 71, the second folding drive roller 53a is used as the first folding drive roller in the folding mode other than the four-fold folding. The first fold motor (DC motor) 65 can be driven at a linear speed that gives priority to productivity. Further, in the four-fold folding mode, the second folding driving roller 53a can be driven separately from the first folding driving roller 53b by a second folding motor (stepping motor) 71. Therefore, the second folding motor 71 that is a stepping motor can accurately control the driving of the second folding driving roller 53a, and the driving load applied to the second folding motor 71 can be reduced as much as possible, thereby preventing the step-out.

  The drive source of the second folding roller can be switched between the first folding motor and the second folding motor with simple control to turn on and off the first electromagnetic clutch and the second electromagnetic clutch.

  When the sheet sensor 81 detects the sheet, the driving of the second folding drive roller 53a is stopped, so that when the sheet is conveyed to the second folding unit 31, the driving of the second folding drive roller 53a is automatically performed. Can be stopped.

  Since the sheet sensor 81 is provided from the third folding nip 78 at a distance that is 1/4 of the conveyance direction length P of the smallest acceptable sheet, the sheet is detected by one sheet sensor 81. At the same time, it is possible to detect a jam at the third folding nip 78 of the sheet that has been folded twice by Kannon quadruple regardless of the sheet size.

  Since the sheet sensor 81 is provided from the third folding nip 78 at a distance of 1/4 of the conveyance direction length P of the smallest acceptable sheet, the third folding nip of the Z-folded sheet is provided. The jam at 78 can be detected regardless of the sheet size.

  After the front end of the sheet folded at the first folding portion 19 abuts against the third stopper 61 to bend the sheet by a predetermined amount α, the guide member 77 is displaced from the retracted position to the guide area and is applied to the sheet. Since the contact is made, the accuracy of the final folding position of the Kannon quadruple can be improved.

  Since the sheet feed amount α is set to 5 mm to 20 mm, the sheet feed amount is too small to prevent the last folding position from shifting and the sheet feed amount is too large to be folded inward at the first and second times. It can prevent that the front-end | tip part of the folded sheet | seat is folded again.

  The image forming system 1 including the sheet folding device 5 that exhibits the same effect as described above can be provided.

  Next, other embodiments will be described. In the following description, parts having the same functions and effects as those of the first embodiment described above are denoted by the same reference numerals, and detailed description of the parts is given. In the following description, differences from the first embodiment will be mainly described.

  A second embodiment will be described with reference to FIG. FIG. 8 is a longitudinal sectional view around the second folding portion of the sheet folding apparatus according to the second embodiment, and shows a state in which the sheet has entered the second folding portion.

  In the second embodiment, the sheet sensor 81 is placed on the sixth conveyance path 25 (upstream of the nip between the second folding driven roller 53b and the second driven roller 55) and from the third folding nip 78 along the sheet conveyance path. At a distance P / 4. The control unit 75 is not provided with the drive pulse number counting unit 87.

  In the second embodiment, when the final folding in the Kannon quad folding mode is performed, the linear speed of the second folding driving roller 53a is controlled to be slower than the linear speed of the first folding driving roller 51а.

  When the determination unit 85 determines that the sheet sensor 81 has detected the leading edge of the sheet, the processing unit 89 sets the linear speed of the second folding drive roller 53a to ¼ of the linear speed of the first folding drive roller 51а. Then, the front end of the sheet is brought into contact with the third stopper 61 and the guide member 77 is rotated from the retracted position to the guide region while forming a deflection in the direction of the third folding nip 78. When the determination unit 85 determines that the trailing edge of the sheet has been detected by the sheet sensor 81, the processing unit 89 makes the linear velocity of the second folding drive roller 53а the same as the linear velocity of the first folding drive roller 51а, The guide member 77 is rotated from the guide area toward the retracted position.

  According to the second embodiment, when performing the final folding in the Kannon quad folding mode, the linear speed of the second folding driving roller 53a is made slower than the linear speed of the first folding driving roller 51а, so that it is conveyed. The timing of rotation of the guide member 77 with respect to the coming sheet can be made appropriate.

  When the sheet sensor 81 detects the sheet, the line speed of the second folding drive roller 53a is decreased, so that when the sheet is conveyed to the second folding unit 31, the line of the second folding drive roller 53a is automatically set. The speed can be made slower than the linear speed of the first folding drive roller 51a.

  Since the linear speed of the second folding driving roller 53a is made slower than the linear speed of the first folding driving roller 51a only while the sheet sensor 81 is detecting the sheet, a decrease in productivity in the quadruple-fold quadruple mode is minimized. Can be suppressed.

  While the linear speed of the second fold drive roller 53a is slower than the linear speed of the first fold drive roller 51a, the displacement of the guide member 77 from the retracted position to the guide area is completed and the second fold drive roller 53a is completed. Since the guide member 77 is moved from the guide region to the retracted position after the linear velocity is restored, the timing of displacement of the guide member 77 can be made appropriate while minimizing the productivity reduction.

  In addition, this invention is not limited to the above-mentioned embodiment, A various deformation | transformation is possible in the range which does not deviate from the summary. In all the embodiments described above, a copying machine is used as the image forming apparatus 3, but a printer, for example, may be used.

  In all the embodiments described above, the sheet binding device 7 is installed on the downstream side of the sheet folding device 5, but for example, a sheet punching device may be installed.

  In general, the thicker the sheet, the higher the sheet is pushed up by the guide member 77. Therefore, in the operation panel 4, the sheet thickness can be selected from a small mode (0.05 mm to 0.10 mm), a medium mode (0.10 mm to 0.15 mm), and a large mode (0.15 mm to 0.20 mm). For example, the sheet feed amount α may be increased as the sheet thickness increases, such as 7 mm in the small mode, 12 mm in the medium mode, and 17 mm in the large mode. As the thickness of the sheet increases, the amount of bending of the sheet can be increased, so that the folding position can be prevented from shifting upward.

  In the second embodiment, the linear speed of the second folding drive roller 53a is set to ¼ of the linear speed of the first folding drive roller 51а. However, the linear speed is not limited to this, for example, 1/3, 1/2, and 3 / 4 may be used.

(A) is a longitudinal cross-sectional view of the periphery of the second folding portion of the sheet folding apparatus according to the first embodiment, and shows a state in which the leading edge of the sheet is detected by a sheet sensor. (B) is a longitudinal cross-sectional view of the periphery of the second folding portion of the sheet folding apparatus according to the first embodiment, and shows a state in which the leading end of the sheet is in contact with the regulating member. (A) is a longitudinal cross-sectional view of the periphery of the 2nd folding part of the sheet folding apparatus which concerns on 1st Embodiment, and is a figure which shows the state by which the sheet | seat is guided to the 2nd folding nip. (B) is a longitudinal cross-sectional view of the periphery of the second folding portion of the sheet folding apparatus according to the first embodiment, and shows a state where the sheet is conveyed while being sandwiched by a second folding nip. It is a longitudinal cross-sectional view around the 1st folding part and 2nd folding part which concern on 1st Embodiment, and is a figure which shows the drive structure of a 1st folding drive roller and a 2nd folding drive roller. It is a top view of the 1st folding part and 2nd folding part periphery which concern on 1st Embodiment, and is a figure which shows the drive structure of a 1st folding drive roller and a 2nd folding drive roller. It is a longitudinal section showing a schematic structure of a sheet folding device concerning a 1st embodiment. It is a block diagram which shows the structure of control of the sheet folding apparatus which concerns on 1st Embodiment. It is a flowchart which shows control of the sheet folding apparatus which concerns on 1st Embodiment. It is a longitudinal cross-sectional view of the 2nd folding part periphery of the sheet folding apparatus which concerns on 2nd Embodiment, and is a figure which shows the state which the sheet | seat has entered into the 2nd folding part.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Image forming system 3 Image forming apparatus 5 Sheet folding apparatus 19 1st folding part 31 2nd folding part 51a 1st folding drive roller (folding roller of 1st folding part)
51b First folding driven roller (folding roller at the first folding part)
51c 1st folding driven roller (folding roller of the 1st folding part)
52 First folding nip (folding nip of the first folding part)
54 Second folding nip (final folding nip of the first folding part)
61 Third stopper (regulating member)
65 First folding motor 67 First electromagnetic clutch (first clutch)
71 Second folding motor 73 Second electromagnetic clutch (second clutch)
77 Guide member 78 Third fold nip (fold nip of the second fold)
81 Sheet sensor (sheet detection means)
α Sheet feed amount

Claims (10)

A first folding section that has a plurality of folding rollers that form two folding nips and that folds the conveyed sheet, and has two folding rollers that form one folding nip and is folded by the first folding section. And a guide member for guiding the sheet to the folding nip of the second fold, and the guide member has a guide area for guiding the sheet and a retracted position retracted from the guide area. The folding roller of the first folding part and the folding roller of the second folding part can be driven at different linear speeds, and the sheet is conveyed from one end and the other end of the sheet in the first folding part. Folding is performed so that the one end and the other end are located on the same side with the position at a distance of about 1/4 of the length in the direction as the folding position, and the center position in the sheet conveyance direction is set as the folding position in the second folding portion. Same as folding When the folding of the second folding part is stopped or the linear velocity of the folding roller of the second folding part is made slower than the linear speed of the folding roller of the first folding part, A sheet folding device for guiding a sheet by displacing a member from a retracted position to a guide region ,
A first folding motor that drives the folding rollers of the first folding section and the second folding section; and a second folding motor that drives the folding rollers of the second folding section, and the second folding section according to the selected folding mode. A sheet folding apparatus characterized in that the driving source of the folding roller can be switched between a first folding motor and a second folding motor . The folding roller of the second folding section is connected to the first folding motor via the first clutch and is connected to the second folding motor via the second clutch, and the first clutch and the second clutch are turned on. 2. The sheet folding apparatus according to claim 1 , wherein the driving source of the second folding roller can be switched between the first folding motor and the second folding motor by turning off . A sheet detection unit is provided between the final folding nip of the first folding unit and the folding nip of the second folding unit in the sheet conveyance path, and the folding roller of the second folding unit is driven when the sheet detection unit detects a sheet. 3. The sheet folding apparatus according to claim 1, wherein control is started . The sheet detecting means is provided at a position at a distance of ¼ of the length in the conveyance direction of the smallest acceptable sheet along the sheet conveyance path from the folding nip of the second folding unit. The sheet folding apparatus according to claim 3 . A regulating member for determining a folding position in the second folding portion, and a guide member after the sheet is fed or bent by a predetermined amount by abutting the leading end of the sheet folded in the first folding portion against the regulating member. The sheet folding apparatus according to claim 3 , wherein the sheet folding device is displaced from the retracted position to the guide region . 6. The sheet folding apparatus according to claim 5 , wherein the sheet feeding amount after abutting against the regulating member is set to 5 mm to 20 mm . The sheet folding apparatus according to claim 5 or 6 , wherein the sheet feeding amount after being abutted against the regulating member is increased as the thickness of the sheet is increased . In the case where the linear velocity of the folding roller of the second folding portion is slower than the linear velocity of the folding roller of the first folding portion, the linear velocity of the folding roller of the second folding portion is only while the sheet detecting means detects the sheet. The sheet folding device according to any one of claims 3 to 7 , wherein the sheet folding device is slowed down . When the linear speed of the folding roller of the second folding part is slower than the linear speed of the folding roller of the first folding part, the retracting position of the guide member while the linear speed of the folding roller of the second folding part is slowed down The guide member is displaced from the guide region to the retracted position after the displacement from the guide region to the guide region is completed and the linear velocity of the folding roller of the second folding unit is the same as the linear velocity of the first folding roller. The sheet folding apparatus according to any one of claims 3 to 8 . An image forming apparatus that forms a read image on a sheet, and the sheet folding apparatus according to claim 1, wherein the sheet folding apparatus is provided on a sheet image-formed by the image forming apparatus. An image forming system characterized in that folding is performed by the method .

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